Inhalable anesthetics are typically volatile substances with relatively low boiling points and high vapor pressures. They can be flammable and explosive substances in both their liquid and vapor states. Further, inhalation of the vapor by health care personnel using them can cause drowsiness.
Therefore, such anesthetics must be safely handled in operating rooms in order to minimize the risk of inhalation by medical personnel as well as to minimize the risk of fire or explosion. Preferably, the anesthetic should be used in a way which will ensure that there is little or no release to the atmosphere at all stages of handling during normal surgical procedures.
Anesthetics are typically dispensed in liquid form to an apparatus, such as an anesthetic vaporizer, which mixes the anesthetic with oxygen and nitrous oxide. The mixture is supplied in gaseous form to the patient for inhalation.
Devices have been designed for the transfer of an anesthetic from a supply container to a vaporizer through a closed system that eliminates the escape of an anesthetic gas to the atmosphere. The devices are designed so that during set-up and disassembly procedures, a supply container of anesthetic is not open and exposed to the atmosphere in the operating room.
One system which has been developed for connecting an anesthetic container to a vaporizer employs a connector tube having adaptors at both ends. The tube is flexible and is kink-resistant. The vaporizer end of the tube is provided with a vaporizer adaptor that engages an anesthetic vaporizer. The end of the tube attached to the anesthetic container is provided with a closure adaptor that engages a closure on the anesthetic container.
The closure is preferably connected to the supply container prior to use in the operating room. The container closure has a frangible seal adapted to be perforated by a piercing means within the closure adaptor as the adaptor engages the closure. Following perforation of the frangible seal by the piercing means, the closure adaptor and closure remain locked together, and this permits the transport of anesthetic through the tube from the supply container to the vaporizer. The system remains closed to the atmosphere throughout the assembly or disassembly procedures.
Further, some types of vaporizers are intended for use with only a specific anesthetic or anesthetics. In such situations, care must be taken to insure that only the proper anesthetic is dispensed into the particular vaporizer. Connecting devices have been designed with keying systems to prevent the use of a vaporizer with an anesthetic for which it is not designed.
In particular, the anesthetic container closure has a specific shape, and the connector tube closure adaptor has a complementary shape for mating with the container closure. At the other end of the container tube, the adaptor has a special shape for mating with a complementary portion of the vaporizer anesthetic inlet port. Because the container for each type of anesthetic has its own special closure shape, and because the corresponding connector device fits only the type of vaporizer designed for that anesthetic, the probability of inadvertently using an anesthetic in an incompatible vaporizer, or of administering an incorrect anesthetic to a patient, is greatly reduced, if not eliminated.
Although such keyed, connector tubes function satisfactorily, there are inventory, installation, and management considerations associated with their use. In particular, such connector tubes are typically provided to the user initially unattached to the vaporizer or the anesthetic container. Thus, such connector tubes must be stored and maintained at an appropriate location for use, and such connector tubes can become misplaced.
Because such connector tubes are not inexpensive, it would be desirable to provide an improved connector device that is less likely to be misplaced. Further, it would be advantageous to provide an improved system which is less expensive and even easier to use.
The above-described flexible tube connector must be held and properly manipulated as the anesthetic container is attached. Further, once attached, the container must be properly inverted and maintained in a generally inverted position so as to permit the anesthetic liquid to flow into the vaporizer. During this process, the flexible tube connector must be maintained at an elevation which is at or above the vaporizer inlet, and the connector must be maintained in an orientation that does not occlude the internal flow path.
Further, after the anesthetic liquid has drained from the container into the vaporizer, care must be taken in removing the container from the connector. Proper procedures must be followed to minimize the likelihood that a significant amount of residual anesthetic liquid in the container or flexible tube connector will drip or leak out as the container is disconnected.
It would be desirable to provide an improved connector which can be readily placed in a receiving orientation wherein the anesthetic container can be easily attached to the connector. Preferably, in this orientation the connector should function in a self-maintained, closed condition wherein the connector occludes flow of the liquid anesthetic out of the vaporizer and wherein the connector also occludes the connected container to prevent escape of the anesthetic liquid or vapor.
Further, it would be advantageous if such an improved connector could readily accommodate repositioning to a self-maintained orientation for accommodating the emptying of the anesthetic container into the vaporizer while the container is in a generally inverted position.
Additionally, such an improved connector should desirably accommodate removal of the empty anesthetic container. To this end, the improved connector should preferably have a self-maintained draining position to accommodate the draining of any residual anesthetic liquid in the top of the container and/or connector into the bottom of the container prior to removal of the container.
The present invention provides an improved connector which can accommodate designs having the above discussed benefits and features.